Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 121
Filter
Add more filters











Publication year range
1.
Nat Prod Res ; : 1-7, 2024 Oct 07.
Article in English | MEDLINE | ID: mdl-39371032

ABSTRACT

Gardeniae Fructus, the dried fruit of Gardenia jasminoides, was fermented with Aspergillus niger DQWM-G11. The antibacterial activities of the fermented and non-fermented products were measured and the transformation of chemical constituents was detected. The results revealed that A. niger DQWM-G11 fermented Gardeniae Fructus (AFGF) possessed a stronger antibacterial effect with a minimal inhibitory concentration (MIC) value of 256 µg/mL, compared to the raw material (MIC: > 1024 µg/mL). An undescribed microbial transformation reaction was discovered, where geniposide (1) was transformed into 1ß-methoxyl-4-epigardendiol (2), which was then verified. The produced component exhibited a stronger antibacterial effect (MIC: 256 µg/mL) than raw geniposide (1) (MIC: >1024 µg/mL), indicating that the increased activity of Gardeniae Fructus was due to the biotransformation. The discovery of this microbial transformation reaction will provide an important theoretical basis for further developing and applying Gardeniae Fructus and geniposide.

2.
Ecotoxicol Environ Saf ; 285: 117103, 2024 Sep 25.
Article in English | MEDLINE | ID: mdl-39326354

ABSTRACT

Aging petrochemical landfills serve as reservoirs of inorganic and organic contaminants, posing potential risks of contamination to the surrounding environment. Identifying the pollution characteristics and elucidating the translocation/ transformation processes of typical contaminants in aging petrochemical landfills are crucial yet challenging endeavors. In this study, we employed a combination of chemical analysis and microbial metagenomic technologies to investigate the pollution characteristics of benzene, toluene, ethylbenzene, and xylene (BTEX) as well as metal(loid)s in a representative aging landfill, surrounding soils, and underlying groundwater. Furthermore, we aimed to explore their transformations driven by microbial activity. Our findings revealed widespread distribution of metal(loid)s, including Cd, Ni, Cu, As, Mn, Pb, and Zn, in these environmental media, surpassing soil background values and posing potential ecological risks. Additionally, microbial processes were observed to contribute significantly to the degradation of BTEX compounds and the transformation of metal(loid)s in landfills and surrounding soils, with identified microbial communities and functions playing key roles. Notably, co-occurrence network analysis unveiled the coexistence of functional genes associated with BTEX degradation and metal(loid) transformation, driven primarily by As, Ni, and Cd. These results shed light on the co-selection of resistance traits against BTEX and metal(loid) contaminants in soil microbial consortia under co-contamination scenarios, supporting microbial adaptive evolution in aging petrochemical landfills. The insights gained from this study enhance our understanding of characteristic pollutants and microbial transformation processes in aging landfills, thereby facilitating improved landfill management and contamination remediation strategies.

3.
Sheng Wu Gong Cheng Xue Bao ; 40(9): 2884-2898, 2024 Sep 25.
Article in Chinese | MEDLINE | ID: mdl-39319713

ABSTRACT

Carbon capture, utilization and storage is the vital technology for China to achieve the goals of carbon peaking and carbon neutrality. Microbial activities in situ are an indispensable part in the process of geological CO2 sequestration. Some microorganisms can convert CO2 into methane and organics as the resource for utilization or into carbonate to achieve long-term sequestration. These activities contribute to the stable storage of CO2 and even negative carbon emission. This paper focuses on the processes of bio-methanation, bio-liquefaction, and bio-precipitation that may be involved in CO2 sequestration in deep stratum and discusses the research progress in the bio-transformation pathways. Bio-methanation and bio-liquefaction can convert CO2 into methane or high-value organic compounds to realize resource reuse. The two technologies can be used alone or coupled to expand the application range of CO2 biotransformation. Bio-mineralization can convert CO2 into calcite by microorganism-induced carbonate precipitation, being a technology of great potential in fixing CO2 and limiting CO2 escape. At present, this field is still in the infancy stage, and there is an urgent need to establish and improve the theoretical and technical systems of CO2 in-situ biotransformation from transformation principle, influencing factors, conversion efficiency, economy, environmental protection, and technological conditions. Moreover, it can be combined with CCUS to establish a technical system integrating capture, transport, displace, storage, transfer, and exploit, so as to promote the value-added application of CCUS and the achievement of carbon peaking and carbon neutrality.


Subject(s)
Carbon Dioxide , Carbon Sequestration , Methane , Carbon Dioxide/metabolism , Methane/metabolism , Biotransformation , Bacteria/metabolism , Calcium Carbonate/metabolism , Calcium Carbonate/chemistry
4.
Molecules ; 29(15)2024 Jul 25.
Article in English | MEDLINE | ID: mdl-39124898

ABSTRACT

By allowing coal to be converted by microorganisms into products like methane, hydrogen, methanol, ethanol, and other products, current coal deposits can be used effectively, cleanly, and sustainably. The intricacies of in situ microbial coal degradation must be understood in order to develop innovative energy production strategies and economically viable industrial microbial mining. This review covers various forms of conversion (such as the use of MECoM, which converts coal into hydrogen), stresses, and in situ use. There is ongoing discussion regarding the effectiveness of field-scale pilot testing when translated to commercial production. Assessing the applicability and long-term viability of MECoM technology will require addressing these knowledge gaps. Developing suitable nutrition plans and utilizing lab-generated data in the field are examples of this. Also, we recommend directions for future study to maximize methane production from coal. Microbial coal conversion technology needs to be successful in order to be resolved and to be a viable, sustainable energy source.

5.
Sci Total Environ ; 951: 175500, 2024 Nov 15.
Article in English | MEDLINE | ID: mdl-39151637

ABSTRACT

Arsenic pollution in paddy fields has become a public concern by seriously threatening rice growth, food security and human health. In this review, we delve into the biogeochemical behaviors of arsenic in paddy soil-rice system, systemically revealing the complexity of its migration and transformation processes, including the release of arsenic from soil to porewater, uptake and translocation of arsenic by rice plants, as well as transformation of arsenic species mediated by microorganism. Especially, microbial processes like reduction, oxidation and methylation of arsenic, and the coupling of arsenic with carbon, iron, sulfur, nitrogen cycling through microbes and related mechanisms were highlighted. Environmental factors like pH, redox potential, organic matter, minerals, nutrient elements, microorganisms and periphyton significantly influence these processes through different pathways, which are discussed in this review. Furthermore, the current progress in remediation strategies, including agricultural interventions, passivation, phytoremediation and microbial remediation is explored, and their potential and limitations are analyzed to address the gaps. This review offers comprehensive perspectives on the complicated behaviors of arsenic and influence factors in paddy soil-rice system, and provides a scientific basis for developing effective arsenic pollution control strategies.


Subject(s)
Arsenic , Biodegradation, Environmental , Oryza , Soil Pollutants , Soil , Arsenic/analysis , Soil Pollutants/analysis , Soil/chemistry , Agriculture/methods , Environmental Pollution/prevention & control , Environmental Restoration and Remediation/methods
6.
Front Cell Infect Microbiol ; 14: 1371312, 2024.
Article in English | MEDLINE | ID: mdl-39035357

ABSTRACT

The symbiotic relationship between the human digestive system and its intricate microbiota is a captivating field of study that continues to unfold. Comprising predominantly anaerobic bacteria, this complex microbial ecosystem, teeming with trillions of organisms, plays a crucial role in various physiological processes. Beyond its primary function in breaking down indigestible dietary components, this microbial community significantly influences immune system modulation, central nervous system function, and disease prevention. Despite the strides made in microbiome research, the precise mechanisms underlying how bacterial effector functions impact mammalian and microbiome physiology remain elusive. Unlike the traditional DNA-RNA-protein paradigm, bacteria often communicate through small molecules, underscoring the imperative to identify compounds produced by human-associated bacteria. The gut microbiome emerges as a linchpin in the transformation of natural products, generating metabolites with distinct physiological functions. Unraveling these microbial transformations holds the key to understanding the pharmacological activities and metabolic mechanisms of natural products. Notably, the potential to leverage gut microorganisms for large-scale synthesis of bioactive compounds remains an underexplored frontier with promising implications. This review serves as a synthesis of current knowledge, shedding light on the dynamic interplay between natural products, bacteria, and human health. In doing so, it contributes to our evolving comprehension of microbiome dynamics, opening avenues for innovative applications in medicine and therapeutics. As we delve deeper into this intricate web of interactions, the prospect of harnessing the power of the gut microbiome for transformative medical interventions becomes increasingly tantalizing.


Subject(s)
Biological Products , Gastrointestinal Microbiome , Humans , Biological Products/pharmacology , Biological Products/metabolism , Gastrointestinal Microbiome/physiology , Bacteria/metabolism , Bacteria/classification , Animals , Host Microbial Interactions , Symbiosis
7.
Nat Prod Res ; : 1-10, 2024 May 06.
Article in English | MEDLINE | ID: mdl-38710024

ABSTRACT

It is widely recognised that orange peels contain a considerable quantity of phenolics, primarily in the form of glycosides. The process of fermentation holds potential as a viable method for extracting phenolic compounds and facilitating their biotransformation into novel metabolites. The aim of this study was to assess the enhanced release of phenolic compounds through the process of solid-state fermentation of orange peels using microorganisms. Following a 6-day incubation period, the methanol extract obtained from the sample fermented with starter Banh men exhibited the highest concentration of total phenolic compounds (17.57 ± 0.34 mg GAE/g DW) and demonstrated the most significant DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity (55.03%). The Reverse Phase High Performance Liquid Chromatography (RP-HPLC) analysis revealed that the predominant phenolic compounds in all fermented samples were flavonoid aglycones, specifically naringenin, hesperetin, and nobiletin. Conversely, in the unfermented orange peels, the major compound observed was the glycoside derivative hesperidin.

8.
Mycotoxin Res ; 40(2): 295-307, 2024 May.
Article in English | MEDLINE | ID: mdl-38507027

ABSTRACT

Infestation of cereal fields with toxigenic Fusarium species is identified as an environmental source for the mycotoxin deoxynivalenol (DON). During rain events, DON may be washed off from infested plants and enter the soil, where microbial transformation may occur. Although some studies showed DON transformation potential of soil microbial communities in liquid soil extracts, these findings can not be transferred to environmental conditions. Accordingly, microbial transformation of DON in soil has to be investigated under realistic conditions, e.g., microcosms mimicking field situations. In this study, we investigated the potential of soil microbial communities to transform DON in six different agricultural soils at two levels (0.5 and 5 µg g-1). The dissipation and the formation of transformation products were investigated in a period of 35 days and compared to a sterilized control. In addition, we measured soil respiration and applied the phospholipid-derived fatty acid (PLFA) analysis to assess whether soil microbial community characteristics are related to the microbial transformation potential. Dissipation of DON in non-sterilized soils was fast (50% dissipation within 0.6-3.7 days) compared to the sterile control where almost no dissipation was observed. Thus, dissipation was mainly attributed to microbial transformation. We verified that small amounts of DON are transformed to 3-keto-deoxynivalenol (3-keto-DON) and 3-epi-deoxynivalenol (3-epi-DON), which were not detectable after 16-day incubation, indicating further transformation processes. There was a trend towards faster transformation in soils with active and large microbial communities and low fungi-to-bacteria ratio.


Subject(s)
Agriculture , Soil Microbiology , Soil , Trichothecenes , Trichothecenes/analysis , Trichothecenes/metabolism , Soil/chemistry , Microbiota , Fusarium/metabolism , Biotransformation , Fatty Acids/analysis
9.
Chin J Nat Med ; 22(3): 280-288, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38553195

ABSTRACT

In the current study, tea saponin, identified as the primary bioactive constituent in seed pomace of Camellia oleifera Abel., was meticulously extracted and hydrolyzed to yield five known sapogenins: 16-O-tiglogycamelliagnin B (a), camelliagnin A (b), 16-O-angeloybarringtogenol C (c), theasapogenol E (d), theasapogenol F (e). Subsequent biotransformation of compound a facilitated the isolation of six novel metabolites (a1-a6). The anti-inflammatory potential of these compounds was assessed using pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns molecules (DAMPs)-mediated cellular inflammation models. Notably, compounds b and a2 demonstrated significant inhibitory effects on both lipopolysaccharide (LPS) and high-mobility group box 1 (HMGB1)-induced inflammation, surpassing the efficacy of the standard anti-inflammatory agent, carbenoxolone. Conversely, compounds d, a3, and a6 selectivity targeted endogenous HMGB1-induced inflammation, showcasing a pronounced specificity. These results underscore the therapeutic promise of C. oleifera seed pomace-derived compounds as potent agents for the management of inflammatory diseases triggered by infections and tissue damage.


Subject(s)
Camellia , HMGB1 Protein , Sapogenins , Anti-Inflammatory Agents/pharmacology , Inflammation/drug therapy , Seeds , Tea , Animals
10.
Metabolites ; 14(2)2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38392993

ABSTRACT

The synthetic cytokinin forchlorfenuron (FCF), while seemingly presenting relatively low toxicity for mammalian organisms, has been the subject of renewed scrutiny in the past few years due to its increasing use in fruit crops and potential for bioaccumulation. Despite many toxicological properties of FCF being known, little research has been conducted on the toxicological effects of its secondary metabolites. Given this critical gap in the existing literature, understanding the formation of relevant FCF secondary metabolites and their association with mammalian metabolism is essential. To investigate the formation of FCF metabolites in sufficient quantities for toxicological studies, a panel of four fungi were screened for their ability to catalyze the biotransformation of FCF. Of the organisms screened, Cunninghamella elegans (ATCC 9245), a filamentous fungus, was found to convert FCF to 4-hydroxyphenyl-forchlorfenuron, the major FCF secondary metabolite identified in mammals, after 26 days. Following the optimization of biotransformation conditions using a solid support system, media screening, and inoculation with a solid pre-formed fungal mass of C. elegans, this conversion time was significantly reduced to 7 days-representing a 73% reduction in total reaction time as deduced from the biotransformation products and confirmed by LC-MS, NMR spectroscopic data, as well as a comparison with synthetically prepared metabolites. Our study provides the first report of the metabolism of FCF by C. elegans. These findings suggest that C. elegans can produce FCF secondary metabolites consistent with those produced via mammalian metabolism and could be used as a more efficient, cost-effective, and ethical alternative for producing those metabolites in useful quantities for toxicological studies.

11.
Environ Pollut ; 346: 123650, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38402932

ABSTRACT

Anaerobic microbial transformation is a key pathway in the natural attenuation of polychlorinated biphenyls (PCBs). Much less is known about the transformation behaviors induced by pure organohalide-respiring bacteria, especially kinetic isotope effects. Therefore, the kinetics, pathways, enantioselectivity, and carbon and chlorine isotope fractionation of PCBs transformation by Dehalococcoides mccartyi CG1 were comprehensively explored. The results indicated that the PCBs were mainly dechlorinated via removing their double-flanked meta-chlorine, with their first-order kinetic constants following the order of PCB132 > PCB174 > PCB85 > PCB183 > PCB138. However, PCBs occurred great loss of stoichiometric mass balance during microbial transformation, suggesting the generation of other non-dehalogenation products and/or stable intermediates. The preferential transformation of (-)-atropisomers and generation of (+)-atropisomers were observed during PCB132 and PCB174 biotransformation with the enantiomeric enrichment factors of -0.8609 ± 0.1077 and -0.4503 ± 0.1334 (first half incubation times)/-0.1888 ± 0.1354 (second half incubation times), respectively, whereas no enantioselectivity occurred during PCB183 biotransformation. More importantly, although there was no carbon and chlorine isotope fractionation occurring for studied substrates, the δ13C values of dechlorination products, including PCB47 (-28.15 ± 0.35‰ âˆ¼ -27.77 ± 0.20‰), PCB91 (-36.36 ± 0.09‰ âˆ¼ -34.71 ± 0.49‰), and PCB149 (-28.08 ± 0.26‰ âˆ¼ -26.83 ± 0.10‰), were all significantly different from those of their corresponding substrates (PCB85: -30.81 ± 0.02‰ âˆ¼ -30.22 ± 0.21‰, PCB132: -33.57 ± 0.15‰ âˆ¼ -33.13 ± 0.14‰, and PCB174: -26.30 ± 0.09‰ âˆ¼ -26.01 ± 0.07‰), which further supported the generation of other non-dehalogenation products and/or stable intermediates with enrichment or depletion of 13C. These findings provide deeper insights into the anaerobic microbial transformation behaviors of PCBs.


Subject(s)
Chloroflexi , Polychlorinated Biphenyls , Polychlorinated Biphenyls/metabolism , Chloroflexi/metabolism , Biodegradation, Environmental , Chlorine/metabolism , Anaerobiosis , Biotransformation , Carbon/metabolism , Isotopes/metabolism , Dehalococcoides
12.
J Nat Med ; 78(2): 403-410, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38238611

ABSTRACT

Morin is a flavonol having 2',4'-dihydroxy group on B-ring identified especially in Moraceae plants. While morin is widely known, its glycosides are relatively rare. To the best of our knowledge, morin-3-O-glucoside (1) was first reported in 2008. However, the reported chemical shift values of 1 were unsatisfactory with those of the aglycone, morin, which is rather similar to quercetin-3-O-glucoside (2). Therefore, we prepared morin-3-O-glucoside (1) by microbial transformation of morin with Cunninghamella sp., and the NMR assignment was reinvestigated. The microbial culture also produced another compound (3). The NMR and MS analyses of 3 revealed it as a novel compound, morin-2'-O-glucoside (3).In this study, the revision of the NMR assignment of morin-3-O-glucoside (1), and the preparation and structural elucidation of a novel compound, morin-2'-O-glucoside (3), were described.


Subject(s)
Flavones , Flavonoids , Glucosides , Flavonoids/chemistry , Glucosides/chemistry , Glycosides/chemistry , Flavonols
13.
J Asian Nat Prod Res ; 26(2): 269-279, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38078645

ABSTRACT

Microbial transformation of dihydroresveratrol (DHRSV) using Beauveria bassiana has produced two new methylglucosylated derivatives of DHRSV (1 and 2), whose structures were characterized as 4'-O-(4″-O-methyl-ß-D-glucopyranosyl)-dihydroresveratrol (4'-O-MG DHRSV, 1) and 3-O-(4″-O-methyl-ß-D-glucopyranosyl)-dihydroresveratrol (3-O-MG DHRSV, 2) on the basis of spectroscopic methods. They showed moderate SIRT3 agonistic activity, and compound 2 exhibited the best deacetylation of 406.63% at 10 µM. The activity of 2 increased by 3.12-fold compared with that of DHRSV, since 2 performed better in molecular docking assay (GScore -8.445).


Subject(s)
Bibenzyls , Sirtuin 3 , Stilbenes , Methylglucosides/chemistry , Molecular Docking Simulation , Molecular Structure
14.
Article in English | MEDLINE | ID: mdl-37767797

ABSTRACT

OBJECTIVE: This study reports the diversity and community structure differences of the endophytic fungi of Panax japonicus of different ages to obtain novel endophytic fungi with glycoside hydrolytic activity for rare saponins production. METHODS: This study used the high-throughput sequencing method to analyze the diversity and community structure of endophytic fungi of P. japonicus. The endophytic fungi were processed by traditional isolation, culture, conservation, and ITS rDNA sequence analyses. Then the total saponins of P. japonicus were used as the substrate to evaluate the glycoside hydrolytic activity. RESULTS: The composition analysis of the community structure showed that the abundance, evenness, and diversity of endophytic fungi of nine-year-old P. japonicus were the best among all samples. A total of 210 endophytic fungi were isolated from P. japonicus samples and further annotated by sequencing the internal transcribed spacer. Then the biotransformation activity of obtained strains was further examined on total saponins of P. japonicus (TSPJ), with a strain identified as Fusarium equiseti (No.30) from 7-year-old P. japonicus showing significant glycoside hydrolytic activity on TSPJ, including ginsenoside Ro→zinglbroside R1, pseudoginsenoside RT1→pseudoginsenoside RP1, chikusetsusaponin IV→tarasaponin VI and chikusetsusaponin IVa →calenduloside E. CONCLUSION: These results reveal the diversity and community structure differences of the endophytic fungi of P. japonicus with different ages and establish a resource library of endophytic fungi of P. japonicus. More importantly, we identified a valuable endophytic fungus with glycoside hydrolytic activity and provided a promising convenient microbial transformation approach to produce minor deglycosylated ginsenosides.

15.
Methods Mol Biol ; 2704: 3-21, 2023.
Article in English | MEDLINE | ID: mdl-37642835

ABSTRACT

The microbiological transformation of sterols is currently the technological basis for the industrial production of valuable steroid precursors, the so-called synthons, from which a wide range of steroid and indane isoprenoids are obtained by combined chemical and enzymatic routes. These compounds include value-added corticoids, neurosteroids, sex hormones, bile acids, and other terpenoid lipids required by the medicine, pharmaceutical, food, veterinary, and agricultural industries.Progress in understanding the molecular mechanisms of microbial degradation of steroids, and the development and implementation of genetic technologies, opened a new era in steroid biotechnology. Metabolic engineering of microbial producers makes it possible not only to improve the biocatalytic properties of industrial strains by enhancing their target activity and/or suppressing undesirable activities in order to avoid the formation of by-products or degradation of the steroid core, but also to redirect metabolic fluxes in cells towards accumulation of new metabolites that may be useful for practical applications. Along with whole-cell catalysis, the interest of researchers is growing in enzymatic methods that make it possible to carry out selective structural modifications of steroids, such as the introduction of double bonds, the oxidation of steroidal alcohols, or the reduction of steroid carbonyl groups. A promising area of research is strain engineering based on the heterologous expression of foreign steroidogenesis systems (bacterial, fungal, or mammalian) that ensure selective formation of demanded hydroxylated steroids.Here, current trends and progress in microbial steroid biotechnology over the past few years are briefly reviewed, with a particular focus on the application of metabolic engineering and synthetic biology techniques to improve existing and create new whole-cell microbial biocatalysts.


Subject(s)
Bile Acids and Salts , Steroids , Animals , Sterols , Agriculture , Biocatalysis , Mammals
16.
Molecules ; 28(15)2023 Jul 29.
Article in English | MEDLINE | ID: mdl-37570714

ABSTRACT

Secoisolariciresinol (SECO) is one of the major lignans occurring in various grains, seeds, fruits, and vegetables. The gut microbiota plays an important role in the biotransformation of dietary lignans into enterolignans, which might exhibit more potent bioactivities than the precursor lignans. This study aimed to identify, synthesize, and evaluate the microbial metabolites of SECO and to develop efficient lead compounds from the metabolites for the treatment of osteoporosis. SECO was fermented with human gut microbiota in anaerobic or micro-aerobic environments at different time points. Samples derived from microbial transformation were analyzed using an untargeted metabolomics approach for metabolite identification. Nine metabolites were identified and synthesized. Their effects on cell viability, osteoblastic differentiation, and gene expression were examined. The results showed that five of the microbial metabolites exerted potential osteogenic effects similar to those of SECO or better. The results suggested that the enterolignans might account for the osteoporotic effects of SECO in vivo. Thus, the presence of the gut microbiota could offer a good way to form diverse enterolignans with bone-protective effects. The current study improves our understanding of the microbial transformation products of SECO and provides new approaches for new candidate identification in the treatment of osteoporosis.


Subject(s)
4-Butyrolactone , Lignans , Humans , Diet , Lignans/pharmacology , Lignans/metabolism , Butylene Glycols/pharmacology , Butylene Glycols/metabolism
17.
World J Microbiol Biotechnol ; 39(10): 262, 2023 Jul 29.
Article in English | MEDLINE | ID: mdl-37507604

ABSTRACT

Tellurium is a super-trace metalloid on Earth. Owing to its excellent physical and chemical properties, it is used in industries such as metallurgy and manufacturing, particularly of semiconductors and - more recently - solar panels. As the global demand for tellurium rises, environmental issues surrounding tellurium have recently aroused concern due to its high toxicity. The amount of tellurium released to the environment is increasing, and microorganisms play an important role in the biogeochemical cycling of environmental tellurium. This review focuses on novel developments on tellurium transformations driven by microbes and includes the following sections: (1) history and applications of tellurium; (2) toxicity of tellurium; (3) microbial detoxification mechanisms against soluble tellurium anions including uptake, efflux and methods of reduction, and reduced ability to cope with oxidation stress or repair damaged DNA; and (4) the characteristics and applications of tellurium nanoparticles (TeNPs) produced by microbes. This review raises the awareness of microorganisms in tellurium biogeochemical cycling and the growing applications for microbial tellurium nanoparticles.


Subject(s)
Nanoparticles , Trace Elements , Tellurium/chemistry
18.
Water Res ; 243: 120360, 2023 Sep 01.
Article in English | MEDLINE | ID: mdl-37481998

ABSTRACT

1,2,5,6-tetrabromocyclooctane (TBCO) and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE), as safer alternatives to traditional brominated flame retardants, have been extensively detected in various environmental media and pose emerging risks. However, much less is known about their fate in the environment. Anaerobic microbial transformation is a key pathway for the natural attenuation of contaminants. This study investigated, for the first time, the microbial transformation behaviors of ß-TBCO and DPTE by Dehalococcoides mccartyi strain CG1. The results indicated that both ß-TBCO and DPTE could be easily transformed by D. mccartyi CG1 with kobs values of 0.0218 ± 0.0015 h-1 and 0.0089 ± 0.0003 h-1, respectively. In particular, ß-TBCO seemed to undergo dibromo-elimination and then epoxidation to form 4,5-dibromo-9-oxabicyclo[6.1.0]nonane, while DPTE experienced debromination at the benzene ring (ortho-bromine being removed prior to para-bromine) rather than at the carbon chain. Additionally, pronounced carbon and bromine isotope fractionations were observed during biotransformation of ß-TBCO and DPTE, suggesting that C-Br bond breaking is the rate-limiting step of their biotransformation. Finally, coupled with identified products and isotope fractionation patterns, ß-elimination (E2) and Sn2-nucleophilic substitution were considered the most likely microbial transformation mechanisms for ß-TBCO and DPTE, respectively. This work provides important information for assessing the potential of natural attenuation and environmental risks of ß-TBCO and DPTE.


Subject(s)
Flame Retardants , Hydrocarbons, Brominated , Hydrocarbons, Brominated/chemistry , Kinetics , Anaerobiosis , Bromine , Biotransformation , Isotopes
19.
Zhongguo Zhong Yao Za Zhi ; 48(11): 2876-2895, 2023 Jun.
Article in Chinese | MEDLINE | ID: mdl-37381950

ABSTRACT

Microbial transformation is an efficient enzymatic approach for the structural modification of exogenous compounds to obtain derivatives. Compared with traditional chemical synthesis, the microbial transformation has in fact the undoubtable advantages of strong region-and stereo-selectivity, and a low environmental and economic impact on the production process, which can achieve the reactions challenging to chemical synthesis. Because microbes are equipped with a broad-spectrum of enzymes and therefore can metabolize various substrates, they are not only a significant route for obtaining novel active derivatives, but also an effective tool for mimicking mammal metabolism in vitro. Artemisinin, a sesquiterpene with a peroxy-bridged structure serving as the main active functional group, is a famous antimalarial agent discovered from Artemisia annua L. Some sesquiterpenoids, such as dihydroartemisinin, artemether, and arteether, have been developed on the basis of artemisinin, which have been successfully marketed and become the first-line antimalarial drugs recommended by WHO. As revealed by pharmacological studies, artemisinin and its derivatives have exhibited extensive biological activities, including antimalarial, antitumor, antiviral, anti-inflammatory, and immunomodulatory. As an efficient approach for structural modification, microbial transformation of artemisinin and its derivatives is an increasingly popular strategy that attracts considerable attention recently, and numerous novel derivatives have been discovered. Herein, this paper reviewed the microbial transformation of artemisinin and its artemisinin, including microbial strains, culture conditions, product isolation and yield, and biological activities, and summarized the advances in microbial transformation in obtaining active derivatives of artemisinin and the simulation of in vivo metabolism of drugs.


Subject(s)
Antimalarials , Artemisinins , Animals , Antimalarials/pharmacology , Antiviral Agents , Artemether , Mammals
20.
Fitoterapia ; 167: 105510, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37075985

ABSTRACT

Osthole is one of the major constituents in Cnidium monnieri (L.) Cuss. and possesses anti-osteoporosis activity. In this work, the biotransformation of osthole was performed based on the human intestinal fungi Mucor circinelloides. Six metabolites including three new metabolites (S2, S3, S4) were obtained, and their chemical structures were elucidated by spectroscopic data analysis. The major biotransformation reactions involved hydroxylation and glycosylation. In addition, all metabolites were evaluated for their anti-osteoporosis activity using MC3T3-E1 cells. The results demonstrated that S4, S5 and S6 could significantly promote MC3T3-E1 cell growth compared to osthole.


Subject(s)
Coumarins , Fungi , Humans , Molecular Structure , Coumarins/pharmacology , Cell Proliferation
SELECTION OF CITATIONS
SEARCH DETAIL